When your family travels, being away from your household's usual eating and sleeping routines means it's more likely that someone might get sick. It can take time to adjust to the food, water, and air in a new environment. And kids can be especially vulnerable to travel-related problems such as motion sickness, diarrhea, and infections.

But some early planning and smart packing can help you keep the trip healthy for everybody. Here are some things to keep in mind when your family prepares to travel.

Special Considerations for Travel Abroad

If you're heading overseas, start preparing well in advance. For instance, it's important to find out what vaccinations your kids (and even you) might need because:

Different countries have different risks and requirements and may require specific vaccines. For example, your family will need the yellow fever vaccine if you're traveling to sub-Saharan Africa or tropical South America, but not to Eastern Europe.

Some vaccines require more than one dose and are given in a series over a period of days or sometimes weeks.

Most vaccines take time to become effective in your body.

Most immunizations should be given at least 1 month before travel, so try to schedule a doctor's visit 4-6 weeks before your trip. Even if you're leaving in less than 4 weeks, you should still make an appointment, as kids might still benefit from shots or medications.

Depending on your travel plans, your doctor may recommend that in addition to routine immunizations, you and/or your child be vaccinated against:

Although all kids get the measles, mumps and rubella (MMR) vaccine at 12-15 months of age, any who will travel outside the United States before that should get the vaccine as early as 6 months of age.

Also, kids of any age can get malaria so if you're traveling to a country with a malaria risk, talk to your doctor about antimalarial drugs. The doctor will decide the best preventative medication based on your destination and your child's health status.

Ask your doctor or visit the Centers for Disease Control and Prevention (CDC) website for a list of recommended or required vaccinations (the site includes a section devoted to travelers' health that you can search by destination), and be sure to take your child's immunization records with you if you're traveling internationally.

Common Travel Troubles

No matter how far you're traveling, there are some health issues that your family is likely to face, including jet lag, ear discomfort, travel (or motion) sickness, and diarrhea.

Jet Lag

When you fly across time zones, it can take time for your internal body clock to catch up with the local time. For example, if your regular bedtime is 9 p.m. and you travel from New York to California, where the time is 3 hours earlier, you may be ready for bed when it is 6 p.m. in California because you've already been up for the usual amount of time and your body is ready to rest. Chances are you'll probably not go to sleep until the local time is 9 p.m., and then you'll be extra tired because your body has been awake for longer than usual.

In addition to tiredness, jet lag can also cause an upset stomach and even insomnia. Here are some tips for dealing with jet lag:

Ear Pain

It's common for kids to experience ear discomfort during a plane's takeoff and descent caused by pressure in the middle ear as it tries to keep up with the rapidly changing air pressure. Encourage kids to swallow, yawn, or, if they're old enough, chew gum. It may help infants to nurse or suck on a bottle.

All of these things can help kids' ears adjust. You may also want to give your child a pain reliever, such as acetaminophen, 30-60 minutes before takeoff or, if it's a long flight, before landing.

Motion Sickness

Travel (or motion) sickness is caused by a conflict between the eye and ear: The inner ears detect movement, but the eyes — focused within a car or other vehicle — do not. These mixed signals coming into the brain can cause nausea, dizziness, vomiting, paleness, and cold sweats.

Motion sickness often occurs on ships and boats, but it can also affect kids when they travel in planes, buses, and cars. Some ways to help combat travel sickness:

Before you leave, have kids eat a light meal or snack, as motion sickness seems worse on an empty stomach. Provide foods that are easily digested, such as complex carbohydrates, and avoid fatty foods.

Try to avoid eating during short trips. For longer trips, sip drinks and eat light, small meals and snacks.

If your child is feeling sick, provide some blander foods, like crackers.

Encourage kids to look outside the car, rather than inside. They should focus on still objects — not moving ones (like other cars) — or a distant point.

Keep the window open a little to allow fresh air to circulate.

Use a headrest to minimize head movement.

Make frequent stops, if possible, at places like rest stops and parks. And if your child complains of feeling sick and it's safe to stop, a short walk for some fresh air might help.

Diarrhea

Diarrhea and other stomach distress, which can be common during travel, are often caused by bacteria or other germs entering the digestive tract, usually from contaminated food or water. Diarrhea is especially a problem for young kids and infants, who can become dehydrated more quickly than adults.

Water in many developing countries isn't treated in the same way as water supplies in developed nations and may contain bacteria, viruses, and parasites.

Take precautions to ensure the water is safe:

Consider drinking only bottled water when traveling.

Use only purified water for drinking, making ice cubes, brushing teeth, and mixing infant formula and foods.

If you use tap water, boil it first or purify it with an iodine tablet.

Other ways to prevent diarrhea and GI distress:

If you're breastfeeding your infant, continue to do so.

Remind kids to practice the good hand-washing techniques used at home.

Keep pacifiers, teething rings, and toys clean.

Keep an alcohol-based hand sanitizer handy.

Make sure all dairy products are pasteurized.

Fresh fruits and vegetables should be adequately cooked or washed well and peeled.

Meats and fish should be well cooked and eaten just after preparation.

Be Prepared

When you pack, include any medications and other medical supplies you and your family use regularly because they may be hard to find at your destination. Don't forget inhalers, allergy medication, and insulin, if needed.

Other items you might want to pack:

over-the-counter (OTC) pain reliever like acetaminophen

a small first-aid kit that includes antiseptic, antibiotic ointment, bandages, and other OTC medications your doctor may recommend

sunscreen

insect repellent (the most effective ones contain DEET)

waterless alcohol-based hand rubs for when soap and clean water aren't available

Do some research before your trip to find the hospital or medical care facility closest to your destination, particularly if your child has a chronic health condition. If you're traveling overseas, try to find one where English is spoken.

It's also wise to carry a written copy of your child's medical history. Having this available can help health care workers make appropriate decisions about how to treat your child and you won't have to worry about forgetting important information at a time when you're likely to be upset.

A medical history should include:

your name, your child's name, your address and home phone number

your child's blood type

immunization records

your doctor's name, address, and office and emergency phone numbers

the name, address, and phone number of your health insurance carrier, including your policy number

a list of any ongoing health problems, such as diabetes or asthma

a list of any medications your child takes and your pharmacy's name and phone number

And Don't Forget . . .

While you're away, it's important to take the same health and safety precautions as you do at home. These include:

Sun smarts. Watch kids' sun exposure. UV light is especially intense near the equator, at high altitudes, from 10 a.m. to 4 p.m., and where light is reflected off water or snow. Apply a broad-spectrum sunscreen of at least SPF 15 every 2 hours, especially after sweating and water exposure. And bring a hat and sunglasses to keep the sun off of your child's face.

Water safety. It's vital to watch kids at all times around any body of water. Because water safety devices — such as life jackets and goggles — may not be available at your destination, consider bringing these from home if you're planning to spend time on or near water.

Buckle up. If you'll rent a car, you might want to bring your child's car seat with you, as well-maintained and approved seats may be unavailable abroad. As always, kids weighing less than 40 pounds should be properly restrained in a car seat. Kids between 4 and about 8 years old should use a belt positioning booster seat.

Before you leave, consider asking your doctor for other information about how to protect your family from illness and injury during travel. Doing a little planning in advance can help ensure that when the time comes, all you'll have left to do is relax and enjoy your vacation!